In the product shot it looks like a 50 1.4 USM but when he holds it up in the end I think it's the 50mm macro mentioned in the video.

I think my favorite thing about the video is that you can tell throughout the whole thing that he's working really hard to keep a straight face (his facial muscles are really not relaxed). They must have shot each scene a zillion times after he busted out laughing in the middle of each take.